SequenceRecord BAM tags should be stored to FASTQ as well

[rhpvorderman]

Outputting to BAM is all well and good, but minimap2 does not support BAM input.

Minimap2 does support copying tags from the FASTQ file directly to SAM. If dnaio behaves similarly to samtools fastq with tag exporting enabled, the methylation and other information from the BAM tags can be preserved in minimap2.

Minimap2 does not support BAM input. As a result I will push that to a lower priority.